A password manager like bitwarden but distributed that would work in p2p to synchronize the encrypted database.
This way we don’t need to install bitwarden on a server or use third party cloud applications (nextcloud) to synchronize the keepass database between our different devices
I like syncthing but if I tell my father or my mother to install it and configure it… he will never succeed ^^ the interest would be to have an application easily usable by everyone without worrying about the technique or having third party applications to install.